The present invention relates to a process for the production of methionine through the hydrolysis of methionine amide using a catalyst comprising titanium and to use of the process for the industrial production of methionine comprising low amounts of and in some cases, substantially no salt by-products
The hydrolysis of the methionine amide to produce the methionine is a known process. In particular, European Patent Application No228938 discloses a process for the production of methionine by the hydrolysis of the methionine amide using a strong base. A problem with this process is that the acidification step uses a strong acid which results in the co-production of mineral salts such as carbonates, chlorides or sulphates. An additional purification step is generally required to remove the salt.
French Patent Application No. 9814000 attempts to overcome the aforementioned problem through the use of a titanium catalyst in the hydrolysis reaction. The use of a titanium based catalyst is also disclosed in Japanese patent applications 03093753, 03093754, 03093755, 03093756.
We have now found that methionine can be produced in high yields using a specific titanium catalyst. Accordingly, the present invention provides a process for the production of methionine which comprises (a) hydrolysing methionine amide in the presence of a catalyst comprising titanium to produce ammonium methioninate, said catalyst having a porosity of from 5 to 1000 nm, a total pore volume of from 0.2 to 0.55 cm3/g and a surface area of from 30 to 150 m2/g, and (b) a second step of recuperating methionine from the ammonium methioninate salt by removing ammonia.